Research on purification process of AlN source material by two-step sintering method
Aluminum nitride(AlN)crystal,as one of the representatives of ultra-wideband semiconductor materials,has ex-cellent properties such as large bandwidth,high thermal conductivity,and high breakdown field strength,which has impor-tant applications in the fields of deep-ultraviolet optoelectronic devices and high-power electronic devices.During the growth process of AlN crystals,the high O and C content in the AlN source material lead to the high concentration of defects inside the crystals or the growth of polycrystals,which will affect the quality of the AlN single crystals.In this paper,a two-step sintering process was proposed to purify the AlN source material,and the sintered samples were characterized by scan-ning electron microscope(SEM)、oxygen,nitrogen,and hydrogen gas analyzer、carbon and sulfur gas analyzer.The SEM re-sults showed that the particle size of the AlN powder was increased from 1-3 μm to about 100 μm,the specific surface area was reduced,and the adsorption of the O impurities was reduced,and the sintered AlN particles had good crystallinity.The results of oxygen,nitrogen and hydrogen gas analyzer、carbon and sulfur gas analyzer showed that the O impurity content was reduced from 7 900 μg/g to 640 μg/g,and the C impurity was reduced from 420 μg/g to 57 μg/g.In summary,the two-step sintering process was an effective way to control the specific surface area of the AlN source material,which was ca-pable of effectively removing the O,C and other impurities in the AlN source material,and improved the crystalline quality of the AlN source material,laying a foundation for the growth of high-quality AlN crystal.
万方数据
维普
